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By John A. Johnson

"INTRODUCTION The use of wet drilling with adequate ventilation has largely controlled production of dust in drilling rock; however, in some operations, such as shaft sinking and modern tunnel driving, when each of a number of drills is operating in a small cross-sectional area, it is at times difficult to ventilate well enough to keep the dust concentration within desired limits.Some chemical compounds, known as wetting agents, when added to water in small quantities reduce the interfacial tension and make it possible for the solution to wet dust particles more effectively than water alone.This report presents results of tests on the effectiveness of two wetting solutions in reducing the amount of dust produced by wet drilling in basalt.ACKNOWLEDGMENTSThe tests were conducted the Bureau's Mount 'Weather Testing Adit,Mount Weather, The author acknowledges the assistance and cooperation of Wing G. Agnew, superintendent; Marvin M. Revelle, mining-engineering aide; and the rest of the crew at Mount Weather in conducting the tests. C. W. Owings, mining engineer, Safety Division, assisted in conducting some of the first tests and gavel valuable advice and guidance throughout the work and in preparing this report."

Jan 1, 1943

By Terry J. Close

Between 1986 and 1989, at the request of the U. S. Bureau of Land Management, personnel from the U. S. Bureau of Mines Western Field Operations Center studied the highly-mineralized, 25,335-acre, Crack Canyon Wilderness Study Area (UT-060-028A), to evaluate its identified mineral resources. The 16-mi-long, 2-mi to 4-mi-wide stud/ area is on the southeast side of the San Rafael Swell, about 40 mi southwest of Green River, Emery County, southeast-central Utah. The study area is underlain by Mesozoic sedimentary beds. Uranium, the principle mineral resource, occurs in two formations. The principle uranium deposits are in mudstone, sandstone, and conglomerate lenses in the 22-mi-long outcrop of the Triassic Chinle Formation which parallels and straddles the northwest boundary of the study area, Some small low-grade uranium occurrences and an extensive gypsum deposit are hosted by the Jurassic-age rocks that underlie the southeast part of the study area.

Jan 1, 1989

By C. P. Bowie, George L. Gates

"INTRODUCTION Experience in drilling oil and gas wells has shown that the voidance of blow-outs, twist-offs, fishing jobs, loss of circulation, and heaving and caving of shale formations into the drill hole depends largely on how well the drilling-mud fluid serves its purpose. A possible method for the control of the drilling fluids may be seen from a study of the relation between the particle-size distribution and some of the important drilling-fluid properties, such as the ability to build quickly a relatively impervious mud sheath on the wall of the hole in the porous formations penetrated by the bit during drilling operations. In a wartime economy, which urgently requires conservation of steel, proper functioning of the drilling fluid is particularly important because, as Parks 4/ has stated, intelligent use of good drilling fluids makes possible drilling of wells for thousands of feet in open holes without the necessity of setting protective strings of casing to control the movement of salt water, gas, and troublesome formations into the borehole; consequently, especially in deep wells, of proper drilling fluids materially reduces the need for casing and lowers the cost of drilling and completing the wells."

May 1, 1942

By Carl R. Peterson

The Rapidex continuous spiral blast tunneling concept uses a spiral blast pattern that provides efficient slabbing action, continuous progression, and partial self-shielding. A lightly shielded tunneling machine using this concept stays at the face to provide continuous drill, load, shoot, and muck functions. Previous phases proved the effectiveness of the blast pattern in the White Pine Shale tested the design features of the shield and developed a remote loading and shooting capability using inductively initiated blasting caps and a pumpable slurry explosive. Phase IV assembled previously used front-end elements (drill, loading components, shield) on a used Joy loader chassis and added a mucking system television monitoring and remote control elements. Remote television monitored loading shooting and mucking were investigated. Difficulty was experienced in locating previously drilled blastholes near the bottom of the heading and even on the face. These holes often had to be considered as lost. Because of hydraulic system deficiencies and overall congestion of machine elements at the face mucking rates obtainable with remote television monitoring were low (on the order of 16 tons per hour). Performance was good enough to indicate improved rates if more space were available and if extreme thoroughness were not required. Because of the serious nature of the lost hole problem, a new explosive loading scheme was given a preliminary evaluation. The new scheme would require the explosive and the detonating charge to be loaded through the drill steel. If the necessary equipment modifications could he made and if safe, efficient operation were assured, the new scheme would alleviate some of the crowding at the face and would eliminate the lost hole problem.

Jan 1, 1978

By Scott W. Hazen

This report describes the design, analysis, and results of a special experimental mine-sampling project conducted as part of the Bureau of Mines continuing program on sample-methods research. The experimental project was conducted at the Bureau?s Denver Mining Research Center and at the Climax molybdenum mine within the framework of a cooperative research agreement between the Bureau and Climax Molybdenum Co., Division of American Metals-Climax, Inc. The primary objective of the project was to investigate the interrelation-ship between sample volume, number of samples, the standard deviation of an assay distribution, and the precision required for an estimate of grade of ore, and to develop this interrelationship into a relatively simple method of application for use in mine sampling.

Jan 1, 1962

By C. S. Allbright

This report gives the results of analyzing three groups of crude shale oils by the Bureau of Mines procedure:4/ (1) Oils produced by standard Fischer assay determinations on oil shales from Brazil (Paraiba Valley) and the United States (Colorado); (2) oils produced from Brazilian shale by different retorting methods; and (3) oils from high-temperature retorting of Colorado oil shale in the Entrained Solids retort. It is the second in a series presenting data obtained by analyzing crude shale oils from various sources. The series furnishes information on the general characteristics and compositions of a wide variety of shale oils. Use of a standard analytical method on all samples facilitates comparison of different oils. The 18 oil samples analyzed in this project comprised 3 from assays of Brazilian and Colorado oil shales in the Fischer retort, 9 obtained by processing Brazilian shale in various other units, and 6 from entrained solids retorting of Colorado shale at 1,000° to 1,500° F. The crude oils from Brazilian shale contained about half as much nitrogen as the Colorado oils. Properties of the Fischer assay oils from Colorado shales agreed with some data that relate grade of the oil shale with properties of the crude oil from the Fischer assay. Comparison of results from Fischer assays of oils from the foreign and domestic shales shows that the oil from Brazilian shale contains more low-boiling material and less residuum than either of the two from Colorado shale. This fact is reflected in lower specific gravity, viscosity, and carbon-residue values for the Brazilian oil. Retorting Brazilian shale in the Entrained Solids unit at 1,120° F. produced an oil whose boiling range was generally lower than the boiling ranges of oils obtained by processing in three other retorts at conventional temperatures. The quality of crude oils from high-temperature retorting of Colorado shale in the Entrained Solids process varies with retorting temperature. As the temperature is raised within the range 1,000° to 1,500° F., the amount of the naphtha fraction in the crude oil increases to about 35 percent and the aromaticity to 98 percent.

Jan 1, 1956

By Jeffrey M. Listak, Gregory J. Chekan

The U. S. Bureau of Mines is investigating longwall panel layouts to maximize coal recovery and minimize interactive problems in multiple-seam operations. When coalbeds are longwall mined in descending order, the transfer of stress from overlying gate roads is a major design constraint affecting pillar stability in the lower mine. The lower mine gate road pillars must be properly designed to withstand the additional load transfer if gate roads are superpositioned in successive seams. The Bureau's MULSIM/NL model, a boundary element computer program, was used to analyze load transfer mechanics for superpositioned gate road pillars. Analysis of Longwall Pillar Stability (ALPS), an empirically based design method for longwall gate road pillars, was used to calibrate model input parameters. ALPS provided a basis to verify model trends and to recommend limits for safe pillar design when superpositioning longwall gate roads. The attributes of the MULSIM/NL model and ALPS were combined to develop a modified method for estimating pillar stress for multiple-seam cases. The modified method uses a multiple-seam factor (MS) to estimate the stress on superpositioned lower mine gate road pillars. Numerical analysis shows that MS depends on the interburden thickness and pillar width.

Jan 1, 1992

By E. P. Barret

Differences in the reducibility of iron oxide materials have been recognized for a long time. Limonites are deoxidized more readily than hematites, and unaltered magnetites are the most difficult to deoxidize. Sinters are found between hematites and magnetites and vary considerably in reducibility, depending on the sintering practice followed and on the degree of fusion of the product. The increased activity in the beneficiation of taconite recently has made available a new blast-furnace raw material, namely, iron oxide pellets made from magnetic taconite concentrate. Many of the data in this paper apply to these pellets, or glomerules, as they were called when this method of agglomerating iron ores was first considered. To clarify the terms applied to iron oxide materials in this paper, the following definitions are given. Agglomeration is the general term applied to all methods of compacting or consolidating fine iron oxide materials. Sinter is the product from a Dwight-Lloyd or Greenawalt sintering machine. Pellets are formed by balling fine, moist oxide in a rotating drum at room temperature, followed by heating in a shaft furnace to a temperature below that of incipient fusion to develop a permanent bond. Nodules are formed by heating the iron oxide material to incipient fusion in a rotary kiln. Briquets are formed in a mold under pressure, with or without the addition of a binder, and burned to develop a permanent bond.

Jan 1, 1949

By A. L. Engel

[Thi;. re:9ort presents re3ults of investigations of problema a3signed as ore-testing projects to the Ore-Dressing Section, t.fetal1urgica.l Div:biion, of the Bureau of Ii.fines at the .fississippi?Valley E>"'1lcrimcnt Station in rtolla, Ho., durine the fiscal year ended June 30, 1940.]

Jan 1, 1941

By O. S. North

As recently as the late 1920's there Were few indications that a 15-million-dollar-a-year industry would ever grow out of the mineralogic curiosity vermiculite. Today, it is an important industrial commodity, used primarily as an insulating material and lightweight aggregate, but with a wide range of other applications. The quantity of crude vermiculite produced and used in the United States increased 14-fold in the 17 years between 1935 and 1951. The vermiculite minerals are of secondary origin, formed by hydrothermal alteration of an ultrabasic igneous rock, generally pyroxenite, or by alteration of phlogopite or biotite mica or possibly other similar minerals. According to different authorities, vermiculite may originate either by direct hydrothermel means, by the weathering of biotite or phlogopite, or by a combination of these two agencies. Vermiculites frequently occur at or near the contacts of an acid intrusive rock, especially a pegmatite dike, with a basic or ultrabasic country rock.

Jan 1, 1953

By Merwin H. Howes

Gnome shaft, situated about 24 miles southeast of Carlsbad, N. Mex., was designed and sunk by the U.S. Atomic Energy Commission for conducting a peace- time experimental nuclear explosion in the thick salt beds of the Permian Salado formation. Excavation was started July 1, 1960, and completed July 26, 1961. The 10-foot diameter shaft, lined with concrete through the rock section, was sunk 1,216 feet. A drift was driven approximately 1,140 feet on the 1,200- foot level terminating in a shot chamber. On completion of 100 feet of shaft, by means of a truck-mounted crane, facilities were installed for conventional sinking. About 709 feet of rock and 506 feet of salt were encountered in the shaft. Salt beds at this place are reported to be over 1,200 feet thick. The overlying rock section varies greatly in composition and thickness of beds and contains a 28-foot bed of water-bearing dolomite. The aquifer was sealed to facilitate shaft sinking and to prevent water-seepage damage in the salt section of the shaft. Sealing was accomplished by grout injection through holes drilled into the aquifer and by grouting behind the concrete liner.

Jan 1, 1963

By Merwin H. Howes

Gnome shaft, situated about 24 miles southeast of Carlsbad, N. Mex., was designed and sunk by the U.S. Atomic Energy Commission for conducting a peace-time experimental nuclear explosion in the thick salt beds of the Permian Salado formation. Excavation was started July 1, 1960, and completed July 26, 1961. The 10-foot diameter shaft, lined with concrete through the rock section, was sunk 1,216 feet. A drift was driven approximately 1,140 feet on the 1,200-foot level terminating in a shot chamber. On completion of 100 feet of shaft, by means of a truck-mounted crane, facilities were installed for conventional sinking. About 709 feet of rock and 506 feet of salt were encountered in the shaft. Salt beds at this place are reported to be over 1,200 feet thick. The overlying rock section varies greatly in composition and thickness of beds and contains a 28-foot bed of water-bearing dolomite. The aquifer was sealed to facilitate shaft sinking and to prevent water-seepage damage in the salt section of the shaft. Sealing was accomplished by grout injection through holes drilled into the aquifer and by grouting behind the concrete liner.

Jan 1, 1963

By A. L. Engel

[This report presents results of investigations of problems assigned as ore-testing projects to the Ore-Dressing Section, Metallurgical Division, of the Bureau of Mines at the Mississippi Valley Experiment Station in Rolla, Mo., during the fiscal year ended June 30, 1940.]

Jan 1, 1941

By G. W. Jones

"INTRODUCTION As part of its work in promoting safety, the Bureau of Mines is investigating various means of eliminating or mitigating the explosion hazards of combustible gases encountered in mining and industry. Information has been obtained and a procedure developed whereby the explosibility of many complex gaseous mixtures may be calculated in a rather simple manner without the necessity of performing laborious laboratory experiments. An earlier publication 3/ described the method of determining by calculation the limits of inflammability of gaseous mixtures, including methane, hydrogen, carbon monoxide, nitrogen, carbon dioxide, and oxygen. The information published in the above report permitted calculation of the limits of inflamnability of such gases as are liberated by mine fires, gases from explosives, automobile exhaust gases, gases present after mine explosions, blast-furnace gas, and other gases of similar type.Gases liberated in certain potash mines in the western part of the United States sometimes contain ethane, in addition to the gases named. An investigation was made to obtain data from which the limits of inflammability of such gaseous mixtures could be determined by calculation. 4/Similar data have been Published covering all types of natural gases containing wide ranges of concentration of nitrogen and carbon dioxide.5/"

Dec 1, 1944

By Richard F. Hewlett

This report describes how a limited number of preliminary exploration drill-hole assays from a mineral deposit can be used to design grid spacing that is both economic and efficient for subsequent evaluation drilling of that deposit. Relationships between desired precision of the estimate of grade of ore and drilling cost are used to determine the economic drill-hole spacing. The statistical concept of precision in estimating grade of ore is used to determine the efficient drill-hole spacing. Assay data from approximately 50 known copper deposits were studied, and the relationships of the statistical parameters of these deposits were computed. Drilling requirements for various precisions of the estimates of grade of ore were computed for some of these known deposits to serve as guides for drilling future copper deposits. The effect of various geologic factors on the trend in grade of ore and, therefore, on the drilling requirements is shown for certain deposits.

Jan 1, 1965

By EDGAR K. SOPER, Clarence A. Wright, DOUGLAS C. LIVINGSTON, Thomas Varley

In 1917 the Federal Bureau of Mines and the University of Idaho arranged to cooperate in an investigation looking to the improvement of mining and milling methods in the mining districts of the State of Idaho, with an especial view to the wider development of the minerul deposits and greater efficiency in the treatment of the lowgrade ores of the State. This work has been made possible lnrgely through the generosity and active assistance of the mine operators, especially certain companies in the Coeur d'Alene region. As the first step in the work under the cooperative agreement it wa.s decided to gather all data possible on the various mining districts throughout the State, both active and abandoned, in order to ascertain their potential possibilities, especial attention being paid to methods of metallurgical treatment and to the solution of the many metallurgical problems in order to effect a greater commercinl saving. With this plan in view, field work was begun in the latter part of May, 1917, and was continued during the summer. E. K. Soper, formerly professor of mining, University of Idaho, and now dean of the mining department of Oregon Agricultural • College, Corvallis, Oreg., visited the mining districts in central and southwestern Idaho and also some of those in the northern part of the St.ate. D. C. Livingston, professor of geology at the University of Idaho, Moscow, Idaho, also visited some of the mining districts in central Idaho during the summer; in addition, much valuable information he had gathered on former trips to many other districts is included in this report. Credit is also due Mr. Livingston for the maps covering the State, as well as the bibliography nt the end of each chapter. Thomas Varley, superintendent of the Seattle mining experiment station of the Bureau of Mines, spent a short time in the field, principally in the mining districts in central and . northern Idaho, and made a brief visit to the southwestern districts with Mr Soper. The field work of Mr. C. A. Wright, metallurgical engineer of the Bureau of Mines, in direct charge of the cooperative work, was chiefly in the Coeur d'Alene region. Mr. Wright visited nearly all of the mining districts in the region and devoted most of his time to studying the milling methods. The results of the investigation are set 1iorth in this bulletin. The bulletin aims to give the l9Calities of the various mining districts, and the nature of the present operations and those that have been carried on in the past. The geology is discussed only in a general way, the descriptions being intended more especially to bring out the types of ore deposits and the character of the ores, a knowledge of which is essential in determining the proper treatment of the ores. The writers do not wish to imply that all districts mentioned in this bulletin were visited during the summer of 1917, for a great deal of the material has been gathered from other reports, especially from publications of the United States Geological Survey. However, it is hoped that this report will be of help to those who are interested in mining in the State of Idaho. The plan is to continue the field work and subsequently publish the results of the investigations in much more detail, with greater emphasis given the metallurgical treatment of the ores and the problems involved.

Jan 1, 1919

By Norma Golumbic

The primary purpose of the Bergius (hydrogenation of coal) and Fischer-Tropsch (hydrogenation of carbon monoxide) processes is the production of synthetic liquid fuels. This objective is of importance in insuring an adequate supply of motor fuels and lubricating oils in the United States. In the urgency of the basic research and process development work on synthetic liquid fuels, the possibilities for the production of synthetic chemicals inherent in these processes have hitherto received little attention in this country. However, the by-products, as well as the primary products, from the Bergius and Fischer-Tropsch processes are rich source materials for organic chemicals. The overhead oil from liquid-phase hydrogenation of coal, for example, contains benzene, toluene, xylene, cyclohexane, methylcyclohexane, aromatic solvents, about 20 percent tar acids (largely phenol, cresols, and xylenols), and 3 percent nitrogen bases. Wax, alcohols, and acids are by--products of the Fischer-Tropsch synthesis. In addition, techniques have been developed which make possible the production of aliphatic hydrocarbons, alcohols, acids, aldehydes, and other oxygenated organic compounds. These chemicals are more valuable on a unit basis than gasoline. Because of continued rapid expansion of the plastic, resin, lacquer, and solvent industries, larger amounts of many of these chemicals will be needed in the near future.

Jan 1, 1949

By M. H. Kline

The Great Gossan Lead in Carroll County, Va., is one of the largest undeveloped sulfide ore bodies known in the eastern United States. It extends for 16.7 miles along the western slope of the Blue Ridge Mountains (fig. 1). The various known segments of the deposit, extending from the southwest end to the northeast, are: The Great Outburst or Iron Ridge segment, Chestnut Creek, Copperas Hill, Sarah Ellen, Wild Cat, Cranberry, Dalton Hill and offset segment to the south of the Cranberry, Little Reed Island, Little Vine, and the Betty Baker at the northeast end. All of these segments have been explored or mined to various extents in the past for the iron gossan and secondary copper ore. The Great Outburst or Iron Ridge segment is now being mined by the General Chemical Division of the Allied Chemical & Dye Corp. for the sulfur and iron content of the primary ore. These deposits are becoming increasingly of Interest as a. large potential source of iron and sulfur owing to their proximity to Birmingham, where the burned cinder sells at a premium, and to the acid markets of the region.

Jan 1, 1949

By A. J. Kraemer

This paper is the second and concluding report of the results of the twenty-fourth semiannual survey made by the Bureau of Mines of motor gasoline marketed in the United states. The first report on this 1931 survey gave the results of the examination of the gasoline samples in accordance with the new Federal specification for United States Government Motor Gasoline. The present paper reports results of the examination of the gasolines for color, doctor test gravity, end point, per cent recovered copper-dish gum, and steam-oven gum. The retail price and the tax at the time each sample was taken are also reported.

Jan 1, 1932

By Frank E. Scott

During the past year interest in the use of hydrazine and hydrazine hydrate as a fuel has increased in the United States; For this reason it was felt to be desirable to obtain information on the explosives properties (if these materials in order that hazards inherent in their manufacture, storage, transportation, and use might be evaluated.

Jan 1, 1949